Table 2.

Test Characteristics of the Decision Tree With 95% CIs

Variable	Derivation Cohort	Test Cohort
No. of subjects	241	200
No. of true positives	26	17
No. of true negatives	188	139
No. of false positives	25	41
No. of false negatives	2	3
Sensitivity	93 (75–99)	85 (61–96)
Specificity	88 (83–92)	77 (70–83)
Positive predictive value	51 (37–65)	29 (18–43)
Negative predictive value	99 (96–100)	98 (93–99)
Positive likelihood ratio	7.9 (5.4–11.6)	3.7 (2.7–5.2)
Negative likelihood ratio	0.08 (0.02–0.3)	0.2 (0.07–0.6)
Area under the curve	0.95 (0.91–0.99)	0.83 (0.72–0.95)